科学家从6千8百万年之久的恐龙骨中提取软组织
时间:2019-01-03 作者:英语课 分类:VOA2005(上)--环境科学探索
Scientists Extract Soft Tissue from 68-Million-Year-Old Dinosaur 1 Bone
科学家从6千8百万年之久的恐龙骨中提取软组织
U.S. scientists have recovered soft tissue from the bones of a nearly 70-million-year-old dinosaur. If it proves to be original tissue not replaced by some other substance, it would be the first to show such material can last more than a few million years and could provide biological insights into the extinct animals.
When North Carolina State University biologist Mary Higby Schweitzer looked inside a thigh 2 bone of a Tyrannosaurus rex excavated 3 in the northern state of Montana recently, she was surprised by an unexpected find. Typically, only the hard parts of an animal, like the bones or shell, are preserved. But this dinosaur contained what appears to be well preserved soft tissue inside the bone where the marrow 4 once was.
As Ms. Schweitzer reports in the journal Science, she isolated 5 the tissue by dissolving the surrounding bone minerals in a weak acid. What remained appears to be blood vessels 6 and cells still elastic 7 after 68 million years.
Ms. Schweitzer: The thing that was so fascinating for us with this particular dinosaur was that they are transparent 8, they are flexible. The vessels are such that we can actually manipulate them with our probe. The bone matrix itself, once we removed the minerals from it, is stretchy and flexible. And then, of course, the microstructures that look like cells are preserved in every way. The cellular 9 extensions are flexible. And they move in solution just like cells preserved in modern bones.
For comparison, the researchers analyzed 10 soft tissue from an ostrich 11 leg bone because birds are widely believed to have evolved from dinosaurs 12. The dinosaur vessels contained small, reddish-brown dots similar to the nuclei 13 of cells lining 14 ostrich blood vessels. The Tyrannosaurus rex bone also contained structures that looked virtually identical to ostrich bone cells.
There are few examples of prehistoric 15 tissue that are not hard. Such soft material that is preserved is usually not more than a few million years old, such as insects trapped in amber 16 or humans and mammoths in peat or ice. But Ms. Schweitzer says her discovery shows it is now possible to find soft tissue in animals many times older.
Ms. Schweitzer: This preservation 18 to this extent, where you still have original flexibility 19 and transparency has not been noted 20 in dinosaurs before. So we're pretty excited about the find.
If the tissue consists of original material, experts say scientists might be able to extract new information about dinosaurs, especially if they can recover proteins and the genetic 21 material DNA 22.
A deputy editor at the journal Science is Robert Hanson.
Robert Hanson: That is why the discovery described here is so interesting. These findings thus help us understand preservation in the fossil record and ultimately this study may pave the way towards new insights into dinosaur physiology 23 and biochemistry.
But appearances can be deceiving. As a result, the scientists are not claiming their finding is actual proof that the dinosaur tissue is in its native, pristine 24 condition. Ms. Schweitzer is conducting laboratory tests to determine whether it is still made of the molecules 26 that existed in the living animal, or a pliable 27 non-organic compound that has taken their place over the ages.
Ms. Schweitzer: Through further chemical analysis we can learn things like, are their protein fragments preserved? If so, how is the protein the same or different from animals that are alive today? As far as DNA goes, we don't know yet. We're doing a lot of stuff in the lab that looks promising 28 right now.
The North Carolina State University researcher is secretive about those studies, awaiting their final outcome and publication.
David McAlary, VOA news, Washington.
注释:
soft tissue 软组织
dinosaur [5dainEsC:] n. 恐龙
thigh [Wai] n. 大腿
Tyrannosaurus rex [tirAnE5sC:rEs,reks] n. 暴龙
marrow [5mArEu] n. 髓,骨髓
elastic [i5lAstik] adj. 弹性的
probe [prEub] n. 探针,探测器
microstructure [5maikrEu5strQktFE] n. 微观结构,显微结构
ostrich [5CstritF] n. 鸵鸟
amber [5AmbE] n. 琥珀
mammoth 17 [5mAmEW] n. [古生]猛犸,毛象
peat [pi:t] n. 泥煤,泥炭块
biochemistry [5baiEu5kemistri] n. 生物化学
molecule 25 [5mClikju:l] n. [化]分子,些微
pliable [5plaiEbl] adj. 柔软的,圆滑的,柔韧的
- Are you trying to tell me that David was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击?
- He stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。
- He is suffering from a strained thigh muscle.他的大腿肌肉拉伤了,疼得很。
- The thigh bone is connected to the hip bone.股骨连着髋骨。
- The site has been excavated by archaeologists. 这个遗址已被考古学家发掘出来。
- The archaeologists excavated an ancient fortress. 考古学家们发掘出一个古堡。 来自《简明英汉词典》
- It was so cold that he felt frozen to the marrow. 天气太冷了,他感到寒冷刺骨。
- He was tired to the marrow of his bones.他真是累得筋疲力尽了。
- His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
- Patients with the disease should be isolated. 这种病的患者应予以隔离。
- The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
- All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》
- Rubber is an elastic material.橡胶是一种弹性材料。
- These regulations are elastic.这些规定是有弹性的。
- The water is so transparent that we can see the fishes swimming.水清澈透明,可以看到鱼儿游来游去。
- The window glass is transparent.窗玻璃是透明的。
- She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
- Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。
- The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
- The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程,因为对他来说,爱是个不可分析的迷。 来自《简明英汉词典》
- Ostrich is the fastest animal on two legs.驼鸟是双腿跑得最快的动物。
- The ostrich indeed inhabits continents.鸵鸟确实是生活在大陆上的。
- The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
- Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》
- To free electrons, something has to make them whirl fast enough to break away from their nuclei. 为了释放电子,必须使电子高速旋转而足以摆脱原子核的束缚。
- Energy is released by the fission of atomic nuclei. 能量是由原子核分裂释放出来的。
- The lining of my coat is torn.我的外套衬里破了。
- Moss makes an attractive lining to wire baskets.用苔藓垫在铁丝篮里很漂亮。
- They have found prehistoric remains.他们发现了史前遗迹。
- It was rather like an exhibition of prehistoric electronic equipment.这儿倒像是在展览古老的电子设备。
- Would you like an amber necklace for your birthday?你过生日想要一条琥珀项链吗?
- This is a piece of little amber stones.这是一块小小的琥珀化石。
- You can only undertake mammoth changes if the finances are there.资金到位的情况下方可进行重大变革。
- Building the new railroad will be a mammoth job.修建那条新铁路将是一项巨大工程。
- The police are responsible for the preservation of law and order.警察负责维持法律与秩序。
- The picture is in an excellent state of preservation.这幅画保存得极为完好。
- Her great strength lies in her flexibility.她的优势在于她灵活变通。
- The flexibility of a man's muscles will lessen as he becomes old.人老了肌肉的柔韧性将降低。
- The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
- Jim is noted for arriving late for work.吉姆上班迟到出了名。
- It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
- Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
- DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
- Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
- He bought a book about physiology.他买了一本生理学方面的书。
- He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。
- He wiped his fingers on his pristine handkerchief.他用他那块洁净的手帕擦手指。
- He wasn't about to blemish that pristine record.他本不想去玷污那清白的过去。
- A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
- This gives us the structural formula of the molecule.这种方式给出了分子的结构式。
- The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
- Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
- Willow twigs are pliable.柳条很软。
- The finely twined baskets are made with young,pliable spruce roots.这些编织精美的篮子是用柔韧的云杉嫩树根编成的。